Hello, is it possible to include external css references into a portal site page?
An example would be adding font-awesome to be able to include icons for social media links in the footer, ie.:
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
<li><a href="https://twitter.com/<>" aria-label="Twitter"><i class="fa fa-twitter"></i></a></li>
We have tried including the link reference in the header css but it is getting stripped out of the published page.
This documentation might be what you're interested in: Set advanced portal options—Portal for ArcGIS (10.7 and 10.7.1) | ArcGIS Enterprise. I would take a look at the footerLinks section in particular, some examples are given.
The config.js file that you can alter is located at: C:\Program Files\ArcGIS\Portal\customizations\<portal_version>\webapps\arcgis#home\js\arcgisonline. Prior to making any changes to this file, I would recommend making a backup of the existing config.js.
Best of luck!